I searched for this but couldn’t find it. I have a fairly new grand Cherokee 6500 miles I just got my first oil change, when I bought the car I was told by salesman to get it changed every 7500 miles and I know the oil reminder comes on at 7500 because my wife has the same car with more miles. The stealer ship put a sticker on the windshield to have the next oil change in 3000 miles. So my question is what the appropriate mileage for a change is, and I assume the dealer uses non synthetic? I also want to switch to full synthetic but I have the 2 years free maintenance.

Read your owners manual (can download on Jeeps website) and go with what it says. For a 3.6 it is every 8,000 miles or 6 months or when the EVIC tells you to, whichever comes first. (if it was property reset at last oil change). Everybody has their own opinion on oil change intervals and what brand/type to use. Follow what the owners manual says and you will be fine.